Quality Digital DC Clamp-on Ammeters

DC Clamp meter Model

PST-CM01

Clamp on multimeter 10 mA resolution

$249

PST-PR11

Clamp on multimeter 1 mA resolution

$344

This is a very handy tool for engineers working with
batteries, power supplies, chargers, electric bicycles and vehicles. You just
clamp the sensor over one of the current carrying wires and read the amps. No
need to break the circuit because it is contactless. It is much safer than
using an ammeter that is inserted in-line less disturbing to the circuit, and
much more convenient.

Theory of operation: To do a contactless
measurement with the clamp ring this ammeter uses a hall effect device to
measure the axial magnetic field generated in the wire by current flowing
through it. The clamp surrounds the wire, which is creating a magnetic field
around it according to Ampere's Law. The magnetic field is concentrated by an
iron core contained in the clamp. The magnetic field is sensed at an air gap
that contains a semiconductor hall effect detector. Current flowing through the
silicon chip is deflected by the magnetic field creating a voltage
perpendicular to the direction of electron flow. This voltage is detected and
converted to amps by the internal microprocessor and displayed on the LCD
panel.

The direction of the magnetic field depends on the direction of
current flow in the wire and is indicated by the plus and minus ampere
readings. An arrow in the clamp ring indicates the polarity.

These
clamp-on DC reading ammeters are very hard to find, usually digital clamp-on
ammeters are AC only. Since they are so useful in the power supply and battery
industries we hunted these down and can offer them at a very affordable
price.

As an added bonus these also can measure AC current through the
clamp, as well as AC and DC voltage and continuity check through test leads.
This is an essential instrument for auto shops, electronics labs, bicycle
shops, product development labs, wheelchair technicians and everyone who needs
to know how many amps is flowing in a wire. They are good for working in
crowded switch box, panels, and wire harnesses.

We have two models.
The PST-CM01 has a maximum current reading of 200 amps and a resolution of 10
mA. The PST-PR11 has a maximum current reading of 30 amps and an incredible
resolution of 1 mA for DC and 0.1 mA for AC measurements.

Note and
Warning: Many clamp-on meters claim to measure DC current, but when you buy
them the DC measurements are made with leads, not the clamps. We have tested
many clamp-on meters, and unfortunately the cheaper ones on the market have
been useless, or they only measure large DC currents, 100s of amps, not much
use for most engineering.

3-3/4 digit large LCD display providing 4000 count with
symbols

Clamp current test up to 200 Amps DC or 30 Amps DC (or
AC)

Additional voltage, resistance, frequency continuity
check features on the PST-CM01 using leads